package com.atguigu.gulimall.cart.interceptor;

import com.atguigu.common.constant.AuthServerConstant;
import com.atguigu.common.constant.CartConstant;
import com.atguigu.common.vo.MemberRespVo;
import com.atguigu.gulimall.cart.vo.UserInfoTo;
import org.springframework.util.StringUtils;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.util.UUID;

/**
 * @Author : Jungle
 * @Description : 在执行目标方法之前，判断用户的登录状态。
 * 并封装传递给controller目标请求
 *
 * 所有的请求先过拦截器，然后再过controller
 */
public class CartInterceptor implements HandlerInterceptor {

    public static ThreadLocal<UserInfoTo> threadLocal = new ThreadLocal<>();

    /**
     * 目标方法执行之前
     *
     * @param request
     * @param response
     * @param handler
     * @return
     * @throws Exception
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        UserInfoTo userInfoTo = new UserInfoTo();
        //从redis上读取的
        HttpSession session = request.getSession();
        MemberRespVo member = (MemberRespVo) session.getAttribute(AuthServerConstant.LOGIN_USER);
        if (member != null) {
            //用户登录
            userInfoTo.setUserId(member.getId());
        }

        Cookie[] cookies = request.getCookies();
        if (cookies != null && cookies.length > 0) {
            for (Cookie cookie : cookies) {
                //user-key
                String name = cookie.getName();
                if (name.equals(CartConstant.TEMP_USER_COOKIE_NAME)) {
                    userInfoTo.setUserKey(cookie.getValue());
                    //标志位设为true
                    userInfoTo.setTempUser(true);
                }
            }
        }
        //如果没有临时用户，一定分配一个临时用户
        if(StringUtils.isEmpty(userInfoTo.getUserKey())){
            String uuid = UUID.randomUUID().toString();
            userInfoTo.setUserKey(uuid);
        }
        //目标方法执行之前
        threadLocal.set(userInfoTo);
        return true;
    }
    /**
     *
     * 业务执行之后：分配临时用户，让浏览器保存
     *    保存cookie,并设置过期时间（设置保存时间一个月）
     */
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        UserInfoTo userInfoTo = threadLocal.get();


        //如果没有临时用户就加上Cookie，并设置时间为一个月
        //如果没有临时用户一定要保存一个临时用户
      if (!userInfoTo.isTempUser()){
          //持续延长临时用户的过期时间
          Cookie cookie = new Cookie(CartConstant.TEMP_USER_COOKIE_NAME, userInfoTo.getUserKey());
          cookie.setDomain("gulimall.com");
          cookie.setMaxAge(CartConstant.TEMP_USER_COOKIE_TIMEOUT);
          response.addCookie(cookie);
      }
    }
}
